Faulty petcock or carburetor problem?

[Ronni]

I'm in the middle of rebuilding my '85 GS450, and the biggest problem I have is a nasty fuel leak.

Problem description:
When the tank is more than half full, fuel will leak through the petcock, through the carburetors, into the combustion chamber, and then into the oil.

Tests performed:
The petcock has recently been rebuild by a local shop (or at least I paid for it).

I took off the fuel tank, to see if the petcock would keep dry.
My observation is, that when the tank is more than half full, fuel will start dripping from the petcock.

Question
I'm not sure if the petcock is supposed to be completely dry?
Even if fuel can drip from there, isn't it supposed to be stopped by the floats in the carburators?

I appreciate any help, as the owner of the garage is not very happy about my bike leaking fuel all over his floor

[arveejay]

Yes your petcock needs replaced, and your float valves are not stopping fuel flow either.. 2 problems. Petcock rebuild kits are containing wrong size O Rings and don't seal. Either buy new factory petcock or go the pingel route, dealers choice. Float valves are worn out or you may only need adjusted more to the shallower depth. .

Added Info. The O Rings on the float valves are probably shot also and need replaced.

[Ronni]

Thanks for the fast reply!
I think I'll talk to another dealer about this problem, my preferred dealer is not a Suzuki dealer, but I'll see if he can help me anyway.

Thanks again!

[arveejay]

Both jobs are easy, good luck, just ask and someone will advise.

[Detman101]

Meh...Just buy a Pingle petcock for your year bike and take the tank off, drain it into a paint-mixing bucket or something big enough, take off the old petcock, bolt-on the pingle and your petcock issue is over.

Took me an hour on a saturday long ago to do the swap and I haven't had any problems since.



But if your carbs are the issue then you will have to take at least 3 hours and replace the faulty components in your carbs. Adjusting the floats correctly may help also.

[dietcokeking]

When the bike is running, a bit of seepage around the float needles won't be a problem. In fact, it would be a miracle if they sealed perfectly. Because the float needles can't be trusted, a faulty petcock will cause the problem you describe when the bike is not running. New petcocks are available on Ebay for $45. My personal preference is not to bother with any type of rebuild kit on these things, although others have had success.